optimize TFPark create tf model performance (#2694)
optimize TFPark create tf model performance (#2694)

* optimize create tf model

* fix style

* fix style
intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL,intel-analytics/BigDL,intel-analytics/BigDL